Fiber implementation questions

[Ilya Yaroshenko via Digitalmars-d]

Hello,

I am thinking about faster event loop that vibe.d has (does not 
matter what driver are used). I want to implement (at least DIP) 
advanced Fiber yielding loop that can allow to eliminate context 
switching for all kind of event waiters.

Q1: Is it save to detach Fiber context from one thread and attach 
it to another thread?

Q2: core.thread.Fiber implementation looks like GC does not scan 
function stacks for yielded contexts. Why?

Best regards,
Ilya